Dyeing of textile fibers



Patented Apr. 18, 1944 DYEING F TEXTILE FIBERS Cllflord Collier Wilcock, Balford, England, as-

signor to Conrtaulds Limited, London, England,

a British company No Drawing. Application May 30, 1942, Serial No. 445,220. In Great Britain 1111! 17, 1941 4 Claims.

This invention relates to an improvement in the dyeing oi textile fibers and in particular to the dyeing of nylon.

I have found that the afilnity of nylon for certain dyes, and in particular for direct cotton dyestuffs, which normally are not readily taken up by nylon, can be considerably increased by treating the nylon with water, in the liquid state under pressure, at temperatures above 100 centigrade. The extent oi the increase in ailinity depends on the temperature employed and appears to attain its maximum at about 150 centigrade at which temperature boiling water exerts a pressure of about 55 lbs. per square inch.

Th increase in afllnity of nylon by the process according to this invention is not deleteriously aflected by the presence of a small proportion of acid or alkali during the heating. Generally speaking, when the process is carried out at a higher temperature the same result can be obtained in a shorter time.

With acetate and acid dyestufis the effect of the treatment of nylon according to this invention is to give the fiber a better afllnity for these dyestufls at lower temperatures than it previously possessed.

The following examples will serve to illustrate the nature of this invention, which, however, is not limited to these examples.

Example 1 Nylon yarn is treated in an autoclave with water at 150 centigrade for one hour, the pressure inside the autoclave being about lbs. per square inch. It is then dyed at 90 centigrade for one hour in a bath containing 1 per cent of Chlorazol Blue BS (index No. 406), 5 percent of per cent acetic acid and 2 per cent of the material sold under the registered trademark Calgon T (the essential basis 0! which is alkali metaphosphate), 50 parts of the bath be ing used for each part of nylon yarn. The dyebath is practically exhausted and a medium heavy blue shade obtained, whereas without such pretreatment or the nylon yarn. dyeing under similar conditions produces a pale sky blu shade, with an exhaustion of only about 25 per cent.

Example 2 Nylon yarn is treated in an autoclave with water at 130 centigrade at a pressure of 25 lbs. per square inch for one hour, and then dyed as described in the foregoing Example 1. 75 per cent exhaustion of the dyebath is obtained.

What I claim is:

1. A process for improving the aillnity of nylon for direct cotton dyestufls, acetate dyestuffs and acid dyestuffs, which comprises treating the nylon with water in the liquid state under pressure and at a temperature above centigrade.

2. A process for improving the aflinity of nylon for direct cotton dyestuil's, acetate dyestufis and acid dyestuil's, which comprises treating the nylon with water in the liquid state under a pressure of 55 lbs. per square inch and at a temperature of 150 centlgrade.

3. A process for improving the affinity of nylon for direct cotton dyestuils. acetate dyestufl's and acid dyestuils, which comprises treating the nylon with water in the liquid state under a pressure of 25 lbs. per square inch and at a. temperature of centigrade.

4. A process for dyeing nylon which comprises treating the nylon with water in the liquid state under pressure and at a temperature above 100 centigrade and then applying to the treated material a dyestuii selected irom the group consisting oi. direct cotton dyestuils, acetate dyestufis and acid dyestufls.

CIJII'ORD COLLIER WILCOCK. 

